title: Phytochemical changes induced by different nitrogen supply forms and radiation levels in two leafy Brassica species.
abstract: The effect of three different nitrogen (N) supply forms differing in their ammonium-to-nitrate (NH(4):NO(3)) ratio (100% NH(4), 50% NH(4) + 50% NO(3), 100% NO(3)) under three different levels of daily photosynthetic active radiation (PAR) (low, 5.0; medium, 6.8; high, 9.0 mol m(-2) day(-1)) on a range of desirable health-promoting phytochemicals in Brassica rapa subsp. nipposinica var. chinoleifera and Brassica juncea was determined. The 100% NH(4) supply under medium PAR levels led to the highest concentration of glucosinolates based on a low nitrogen/sulfur ratio as well as high levels of carotenoids in the leaves of both Brassica species. However, the 100% NH(4) supply under low and medium PAR levels resulted in low concentrations of flavonoids based on high N concentration in the leaves. Thus, the data provided here have strong implications for crop management strategies aimed at optimizing both the concentration and composition of a range of phytochemicals.
authors.affiliation: Department of Geology and Mechanical Engineering, Bioengineering and Hydraulics for the Territory, University of Tuscia, Viterbo, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Fallovo
authors.forename: Monika
authors.initials: M
authors.lastname: Schreiner
authors.forename: Dietmar
authors.initials: D
authors.lastname: Schwarz
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Colla
authors.forename: Angelika
authors.initials: A
authors.lastname: Krumbein
mesh_terms: D001937:Brassica / Q000737:chemistry*; D002338:Carotenoids / Q000032:analysis; D009584:Nitrogen / Q000032:analysis*; D018515:Plant Leaves / Q000737:chemistry*; D011868:Radioisotopes / Q000032:analysis; D013045:Species Specificity
chemical_list: D011868:Radioisotopes; D002338:Carotenoids; D009584:Nitrogen